Conventionally, a clip may be introduced into a body cavity through an endoscope to grasp living tissue of a body cavity for hemostasis, marking, and/or ligating. In addition, clips are now being used in a number of applications related to gastrointestinal bleeding such as peptic ulcers, Mallory-Weiss tears, Dieulafoy's lesions, angiomas, post-papillotomy bleeding, and small varices with active bleeding.
Gastrointestinal bleeding is a somewhat common and serious condition that is often fatal if left untreated. This problem has prompted the development of a number of endoscopic therapeutic approaches to achieve hemostasis such as the injection of sclerosing agents and contact thermo-coagulation techniques. Although such approaches are often effective, bleeding continues for many patients and corrective surgery therefore becomes necessary. Because surgery is an invasive technique that is associated with a high morbidity rate and many other undesirable side effects, there exists a need for highly effective, less invasive procedures.
Mechanical hemostatic devices have been used in various parts of the body, including gastrointestinal applications. Such devices are typically in the form of clamps, clips, staples, sutures, etc. that are able to apply sufficient constrictive forces to blood vessels so as to limit or interrupt blood flow. One of the problems associated with conventional hemostatic devices, however, is that they can only be delivered using rigid shafted instruments via incision or trocar cannula. Moreover, many of the conventional hemostatic devices are not strong enough to cause permanent hemostasis.
One proposed solution is described in U.S. Pat. No. 5,766,189, which shows a clip device having a pair of arms that are provided with a tendency to open. One problem with this clip and other similar types of clips having a pair of arms is that it may often be necessary to rotate the clip to properly grasp the area to be clipped. Rotation of the clip is often hindered or complicated by the travel of the operating wire through the bends of the tube(s) used to deliver the clip. Accordingly, there is a need for a clip that can be delivered to the target area and used without having to rotate the clip to a desired orientation.
Another problem often encountered with conventional hemostatic devices is the difficulty in securing the clip device to the delivery apparatus prior to reaching the target area within the patient, and then quickly and easily releasing the clip device from the delivery apparatus once the clip has been attached to the target site.
Therefore, there is a need for a release mechanism that may quickly and reliably disengage the clip device from the delivery apparatus once the clip has been attached to the target site.